Thanks to its unbelievable ratings and numerous reruns on channels like TBS, The Big Bang Theory seems to be taking over the world. Following suit is the show's incredibly catchy theme song written and performed by the Barenaked Ladies.

But how did the band best known for singing about chickity China the Chinese chicken wind up creating a TV theme song about the development of the universe? The guys talk about how that all came to be in this behind-the-scenes video, in which co-creator Chuck Lorre also reminiscences about playing guitar with the guys and that one time they showed up for a performance naked. No, really.